NuttX-5.4
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This is the 51st release of NuttX. This release includes one new,
important extension to th NX graphics system (See
https://nuttx.apache.org/docs/latest/components/nxgraphics/index.html).

NX was develop a couple years back on hardware that supported only
framebuffer devices, that is, video hardware with video memory
directly converts the memory content to video. However, most MCUs
that NuttX focuses on do not support such video memory; rather,
that typically only support LCDs via parallel or serial interfaces.

This release of NuttX extends NX so that now renders directly to
the LCD device via its serial or parallel interface. No in-memory
copy of the screen memory need be maintained so this solution should
also work in MCUs with very limited SRAM.

This initial release of this feature includes the verified NX
extensions plus a driver for the HX8347, 16-bit parallel LCD. This
LCD supports 16-bit RGB (5:6:5).
